Pipelines consist of steel tubes having a diameter of 1 m or more. High-alloyed steels are used. Liquids, gases or even also emulsions flow through the pipes. Weak points may develop on the inner side of the pipe on account of corrosion, cavitation or the like. These weak points are located by regularly carried-out inspections. In order to repair pipe portions having weak points of this kind, a bypass of ca. 1,000 m length must be laid.
A method of the generic kind and an apparatus of the generic kind are described in EP 0 561 467 A1. According to this, two or more half shells are placed at a spacing around the pipe of the pipeline. A plastics material is then injected into the gap between the external wall of the pipe and the inner side of the shells.
A method is known from GB 23 96 675 for connecting two plastics pipes to each other by means of an electrically-welded sleeve. A sealing material can be injected between the inner wall of the sleeve and the outer wall of the pipes to be connected to one another.
EP 0 480 686 A1 describes a method for closing an opening in a pipeline with a ceramic plate, which closes the opening and is secured by means of a cement introduced into a casing.